A site having dedicated IP will help or effect anything in search engine rankings as well in any other ways? Similarly having common Ip will affect our site in search engines for any factors?

Looking for expert suggestions....

i have heard ever abt Local working area IP(ISP) and host IP where my site is hosted

Google is smart enough, mostly, to understand shared hosting and not penalize an innocent domain for the misdeeds of others that share the IP. Mostly.

>as well in any other ways?

Email can more easily be affected, example if an email spammer has used the shared IP, some of the dumber filtering systems (like yahoo mail) may just simply blacklist email from all of the domains on the shared IP.

i just came arond the concept of share ip, and yes john google is good enough to know all of the things happens in web market.

It makes no difference at all, HOWEVER the sites do store the IP address for each site.

A less well known Tip: You can go to MSN and search for all sites on an IP address by using IP:xxx.xxx.xxx.xxx. It usually produces interesting results if you do use shared IPs!

I once read a post by Matt Cutts that said if you do have 1,000 sites in your shared hosting that are trying to abuse Google via duplicate content, you will be penalised.